diff --git a/Source/Core/DiscIO/VolumeWiiCrypted.cpp b/Source/Core/DiscIO/VolumeWiiCrypted.cpp
index d956b9444d..dad2977ba0 100644
--- a/Source/Core/DiscIO/VolumeWiiCrypted.cpp
+++ b/Source/Core/DiscIO/VolumeWiiCrypted.cpp
@@ -33,7 +33,7 @@ CVolumeWiiCrypted::CVolumeWiiCrypted(IBlobReader* _pReader, u64 _VolumeOffset,
 	m_LastDecryptedBlockOffset(-1)
 {
 	aes_setkey_dec(m_AES_ctx.get(), _pVolumeKey, 128);
-	m_pBuffer = new u8[0x8000];
+	m_pBuffer = new u8[s_block_total_size];
 }
 
 bool CVolumeWiiCrypted::ChangePartition(u64 offset)
@@ -47,7 +47,6 @@ bool CVolumeWiiCrypted::ChangePartition(u64 offset)
 	return true;
 }
 
-
 CVolumeWiiCrypted::~CVolumeWiiCrypted()
 {
 	delete[] m_pBuffer;
@@ -66,36 +65,42 @@ bool CVolumeWiiCrypted::Read(u64 _ReadOffset, u64 _Length, u8* _pBuffer, bool de
 
 	while (_Length > 0)
 	{
-		static unsigned char IV[16];
-
-		// math block offset
-		u64 Block  = _ReadOffset / 0x7C00;
-		u64 Offset = _ReadOffset % 0x7C00;
-
-		// read current block
-		if (!m_pReader->Read(m_VolumeOffset + m_dataOffset + Block * 0x8000, 0x8000, m_pBuffer))
-			return(false);
+		// Calculate block offset
+		u64 Block  = _ReadOffset / s_block_data_size;
+		u64 Offset = _ReadOffset % s_block_data_size;
 
 		if (m_LastDecryptedBlockOffset != Block)
 		{
-			memcpy(IV, m_pBuffer + 0x3d0, 16);
-			aes_crypt_cbc(m_AES_ctx.get(), AES_DECRYPT, 0x7C00, IV, m_pBuffer + 0x400, m_LastDecryptedBlock);
+			// Read the current block
+			if (!m_pReader->Read(m_VolumeOffset + m_dataOffset + Block * s_block_total_size, s_block_total_size, m_pBuffer))
+				return false;
 
+			// Decrypt the block's data.
+			// 0x3D0 - 0x3DF in m_pBuffer will be overwritten,
+			// but that won't affect anything, because we won't
+			// use the content of m_pBuffer anymore after this
+			aes_crypt_cbc(m_AES_ctx.get(), AES_DECRYPT, s_block_data_size, m_pBuffer + 0x3D0,
+			              m_pBuffer + s_block_header_size, m_LastDecryptedBlock);
 			m_LastDecryptedBlockOffset = Block;
+
+			// The only thing we currently use from the 0x000 - 0x3FF part
+			// of the block is the IV (at 0x3D0), but it also contains SHA-1
+			// hashes that IOS uses to check that discs aren't tampered with.
+			// http://wiibrew.org/wiki/Wii_Disc#Encrypted
 		}
 
-		// copy the encrypted data
-		u64 MaxSizeToCopy = 0x7C00 - Offset;
+		// Copy the decrypted data
+		u64 MaxSizeToCopy = s_block_data_size - Offset;
 		u64 CopySize = (_Length > MaxSizeToCopy) ? MaxSizeToCopy : _Length;
 		memcpy(_pBuffer, &m_LastDecryptedBlock[Offset], (size_t)CopySize);
 
-		// increase buffers
+		// Update offsets
 		_Length -= CopySize;
 		_pBuffer    += CopySize;
 		_ReadOffset += CopySize;
 	}
 
-	return(true);
+	return true;
 }
 
 bool CVolumeWiiCrypted::GetTitleID(u8* _pBuffer) const
diff --git a/Source/Core/DiscIO/VolumeWiiCrypted.h b/Source/Core/DiscIO/VolumeWiiCrypted.h
index 1cca81c410..5e5e1e196d 100644
--- a/Source/Core/DiscIO/VolumeWiiCrypted.h
+++ b/Source/Core/DiscIO/VolumeWiiCrypted.h
@@ -44,6 +44,10 @@ public:
 	bool ChangePartition(u64 offset) override;
 
 private:
+	static const unsigned int s_block_header_size = 0x0400;
+	static const unsigned int s_block_data_size   = 0x7C00;
+	static const unsigned int s_block_total_size  = s_block_header_size + s_block_data_size;
+
 	std::unique_ptr<IBlobReader> m_pReader;
 	std::unique_ptr<aes_context> m_AES_ctx;
 
@@ -53,7 +57,7 @@ private:
 	u64 m_dataOffset;
 
 	mutable u64 m_LastDecryptedBlockOffset;
-	mutable unsigned char m_LastDecryptedBlock[0x8000];
+	mutable unsigned char m_LastDecryptedBlock[s_block_data_size];
 };
 
 } // namespace